Hitoku. That was my name in this world.
My memories of before were like a faded scroll: crowded lecture halls, glowing screens, a manga called Demon Slayer read under dim lamplight. Imagine my surprise when I woke up not in a hospital, but in a rain-soaked ditch in Taisho-era Japan, my body screaming with a foreign, gnawing hunger. It took a night of terror and a bandit's unfortunate encounter to understand my plight.
I was a demon.
A month had passed. My body, wrapped in blood-red bandages scavenged from my victims, felt alien yet powerful. Only my unique feature remained uncovered: the single, large vertical eye in the center of my forehead, a cyan pupil glowing softly in the dark. My two normal eyes stayed closed beneath it, a choice I made. One perfect sense was better than three conflicting ones.
He found me just before dawn. Genji, Kanoe Rank. He moved through the pine forest with a predator's grace, his black uniform blending with the shadows, his white nichirin blade a stark betrayal. He'd tracked me to the bandit camp I'd been using as a larder and a training ground.
"Ah," I muttered, stepping from the ruined shack. The bandits were… spent. "To think a Demon Slayer would find me through this old forest. I took such precautions."
The last thing I wanted was to die a nameless footnote, some Lower Moon wannabe crushed by a Hashira a month into my new, cursed existence. So I had trained. Every night. Pushing this demonic body, testing its limits, understanding the strange, analytic pressure building behind my central eye.
Genji settled into his stance. A seasoned slayer. Level 33. He was not the first I'd met. A Mizunoe using Water Breathing had fallen to my fists a week prior, teaching me the basic rhythm of these battles.
"Demon. Your night ends here. I am Genji of the Demon Slayer Corps."
"I am Hitoku," I said, the smile in my voice genuine. "It means 'One Eye'. Fitting, don't you think?"
My central eye blinked, its cyan glow intensifying as it focused, not on him, but on the path of his blade, the tension in his sword arm. To my eye, his movements seemed outlined in faint, predictive tracers.
"Breath of the Crow. First Form: Sharp Feather Draw!"
He was fast. Incredibly so. His body vanished in a burst of motion, the white blade clearing its sheath with a piercing shriek, cutting up from an impossibly low angle.
But my eye had seen the micro-tremor in his lead foot, the shift of his hip a fraction before the movement. I leaned back, letting the whistling blade pass centimeters from my bandaged chest.
Fascinating, I thought, the analysis coming unbidden. The sound is part of the technique. A psychological feint. The low angle exploits the natural guard posture. Beautiful efficiency.
I let my eye pulse visibly. "A Breathing Style that mimics crows! How wonderfully fitting!"
I saw the flicker in his composure. Good. Demons who talked were one thing. Demons who analyzed their techniques were another.
"Second Form: Murder's Fleet-Step!"
He vanished again, a rustle of feathers. He was suddenly to my left, right, behind—striking like a pecking crow at my joints, my neck, my knees. A harrying, multi-angled assault.
And I met every strike. Not with brute force, but with minimal, precise deflections. A tilt of my wrist redirected a thrust. A shift of my hip avoided a slash at my hamstring. My central eye tracked every arc, every feint, calculating the three most likely follow-ups before Genji's muscles even twitched.
Blood Demon Art: Path of the Perceiving Eye.
No flames. No blood clones. Just absolute, crystalline clarity of prediction. It read the story written in muscle tension, breath release, and gaze focus. To my eye, his elegant, unpredictable style began to look like a sequence of flowing script.
"A flock harries its target," I mused aloud, parrying a jab at my central eye with a clawed finger. "But if one can see each bird's intended flight path…"
I lunged. My hand, hardened and sharp, shot out not to where he was, but where his Fleet-Step was about to take him. He twisted violently, the fabric of his sleeve tearing on my nails.
I saw the realization dawn in his eyes. The desperation. The fight stretched on, minutes passing. He was tiring. I was learning.
"Third Form: Shifting Flock Barrage!"
He spun, a maestro of chaos. The air filled with a lattice of interweaving black-light slashes, a beautiful, chaotic pattern meant to overwhelm and confuse.
I stepped, turned, and wove through them like smoke through a net. A single, shallow line opened on my cheek. I felt the sting, the warm trickle of blood. It was the first hit he'd landed that mattered.
Interesting, my mind hummed. The pattern has a deeper, fractal rhythm. My eye is learning it.
"Wonderful!" I praised, licking the blood. "The pattern seems random, but it has a logic. A murder's logic."
He was panting now. I could see his Vital Force—his Breath Capacity—draining. I pushed, forcing him into defense.
"Fourth Form: Omen's Illusive Guard!"
His blade became a darting, pecking shield, each parry meant to set up a vicious counter. I let him deflect my strikes, watching the automatic counter-thrust patterns emerge in my vision. His blade bit into my thigh, my side. The flesh sizzled, then knitted closed.
"Exhausting, isn't it?" I asked as the moon dipped low. "To feel your every move anticipated?"
Suddenly, I disengaged, leaping to the clearing's edge. "Rest."
He stared, blade trembling. "What?"
"Rest. Drink. Catch your breath." I gestured vaguely towards his canteen. "I am not finished appreciating your technique. It would be a shame if you collapsed before the finale."
The humiliation was a tangible force. But survival was stronger. He knelt, gulping water, his eyes burning with hatred and fear. The eastern sky began to pale.
"Dawn approaches," I noted softly. "The natural conclusion."
A desperate hope flared in him. The sun. His final ally.
"You have shown me everything," I said, my central eye fixed on him, drinking in his exhausted form. "The Sharp Feather. The Fleet-Step. The Shifting Flock. The Illusive Guard. All that remains is the Fifth Form, yes? The culmination. Show me."
It was a gamble. But my eye had parsed the hierarchy of his forms, sensed a pinnacle yet unreached. His Breathing hitched, then smoothed into a final, profound rhythm.
Breath of the Crow, Fifth Form: Black Wing Omen.
He took one deep, world-narrowing breath. He wasn't looking at me; he was looking at my future. He released the breath, and with it, a single, perfect slash. It cut through the air, trailing smoky darkness that swallowed sound and light. It was beautiful. It was unavoidable.
To my normal eyes, perhaps.
To my Perceiving Eye, it was a culmination of every pattern I'd learned. I saw the predictive arc not as a mystery, but as a mathematical certainty. And seeing it, I could choose a variable outside its equation.
I didn't dodge the predicted path. I moved before the prediction was fully formed.
My body, channeling the stolen blueprint of his First Form, became a release of coiled energy. My hand, fingers fused into a blade-like point, shot forward in a whistling, upward arc.
Not with his sword. With my own demon-hardened flesh.
"Sharp Feather Draw."
It pierced his right shoulder with a sickening crunch, pinning him to a thick pine.
He screamed.
My other hand, moving with the flickering multiplicity of his Second Form, stabbed down, shattering his thigh bone.
"Murder's Fleet-Step."
He hung, broken, held up by my impaling arm. Despair flooded his face. The first true ray of dawn gilded the treetops.
I leaned close. My central eye reflected his dying light. "The finale."
I pulled my hand from his shoulder, assumed the defensive coil of his Fourth Form, and unleashed the instantaneous, predictive counter of the Fifth.
My index finger, like a black beak, thrust forward.
It pierced his heart.
His body jerked. The light of the rising sun, beautiful and cruel, fell upon his face. His lips, filling with blood, formed the last, desperate word:
"...How?"
I watched the life leave his eyes, feeling no triumph, only a profound, scholarly satisfaction. My weak little Blood Demon Art. It didn't just track blade paths.
It learned them. It understood the Breath. And once understood…
I pulled my hand free, letting his body slump into the sun-dappled dirt.
…it could be made my own.
A chime, soft and clear, echoed in the silence of my mind.
[You have slain a Lv. 33 Kanoe (Demon Slayer Corps).]
[EXP gained: 132. Bonus EXP for Technique Analysis & Mimicry: +50.]
[Total EXP: 182. Level Up!]
[You are now Lv. 13.]
[Your attributes rise by 3 points each]
[Path of the Perceiving Eyes activated. Your perception rises by 9 points instead of 3]
I looked at the white nichirin blade lying in the dirt. Then I looked east, at the fully risen sun that warmed my bandaged skin without harm. A slow smile spread across my face.
The hunt, and the learning, had only just begun.